Image generating unit and image projecting apparatus

ABSTRACT

An image generating unit includes a fixed unit including a first fixed plate and a second fixed plate; and a movable unit movably supported by the fixed unit. The movable unit includes a movable part movably supported between the first fixed plate and the second fixed plate; an image generating part provided on the movable part and configured to receive illumination light to generate an image; and a heat radiating part coupled to the movable part and configured to radiate heat generated in the image generating part, the second fixed plate being sandwiched between the heat radiating part and the movable part.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119 toJapanese Patent Application No. 2016-051334 filed on Mar. 15, 2016, thecontents of which are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The disclosures herein generally relate to an image generating unit andan image projecting apparatus.

2. Description of the Related Art

An image projecting apparatus, which projects, on a screen or the like,an image generated based on image data received from a personal computer(PC) or the like, for example, is known in the related art.

In such an image projecting apparatus, for example, a method is knownfor shifting optical axes with respect to light beams emitted from aplurality of pixels of a display element to shift the pixels so as todisplay an image with higher resolution than that of the display element(refer to, for example, Japanese Unexamined Patent ApplicationPublication No. 2004-180011).

For an image projecting apparatus, it is preferable not only to enhanceresolution of an image but also to reduce a space required forinstalling the apparatus and to reduce a size and weight of theapparatus so that the apparatus can be easily carried.

SUMMARY OF THE INVENTION

It is a general object of at least one embodiment of the presentdisclosure to provide an image generating unit and an image projectingapparatus that substantially obviate one or more problems caused by thelimitations and disadvantages of the related art.

According to one aspect of the present disclosure, there is provided animage generating unit including a fixed unit including a first fixedplate and a second fixed plate; and a movable unit movably supported bythe fixed unit. The movable unit includes a movable part movablysupported between the first fixed plate and the second fixed plate; animage generating part provided on the movable part and configured toreceive illumination light to generate an image; and a heat radiatingpart coupled to the movable part and configured to radiate heatgenerated in the image generating part, the second fixed plate beingsandwiched between the heat radiating part and the movable part.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an example of an image projectingapparatus according to an embodiment;

FIG. 2 is a block diagram illustrating an example of a configuration ofthe image projecting apparatus according to the embodiment;

FIG. 3 is a perspective view of an optical engine according to theembodiment;

FIG. 4 is a perspective view of an example of a lighting optical systemunit according to the embodiment;

FIG. 5 is a diagram illustrating an example of an internal configurationof a projection optical system unit according to the embodiment;

FIG. 6 is a perspective view of an image generating unit according tothe embodiment;

FIG. 7 is a side view of the image generating unit according to theembodiment;

FIG. 8 is an exploded perspective view of a fixed unit according to theembodiment;

FIG. 9 is a diagram illustrating a structure of supporting a movableplate by the fixed unit according to the embodiment;

FIG. 10 is an exploded perspective view of a movable unit according tothe embodiment;

FIG. 11 is a side view of a movable unit according to the embodiment;

FIG. 12 is an exploded perspective view of an example of a configurationincluding a driving unit according to the embodiment;

FIG. 13 is an exploded perspective view of an example of a configurationincluding a position detecting unit according to the embodiment; and

FIG. 14 is an exploded side view of the example of the configurationincluding the position detecting unit according to the embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, an embodiment of the present disclosure will bedescribed with reference to the accompanying drawings. In the drawings,the same numerals are given to the same elements and overlappingdescriptions may be omitted as appropriate. The present disclosure hasan object to provide an image generating unit that can enhanceresolution of an image and downsize an apparatus.

FIG. 1 is a diagram illustrating a projector 1 according to anembodiment.

The projector 1 is an example of an image projecting apparatus. Theprojector 1 includes a radiation window 3 and an external interface(I/F) 9, and an optical engine, which is configured to generate aprojection image, is provided inside of the projector 1. For example,when image data is transmitted to the projector 1 from a personalcomputer (PC) or a digital camera coupled to the external interface 9,the optical engine generates an image based on the received image dataand projects the image P from the radiation window 3 onto a screen S asillustrated in FIG. 1.

Note that, in the following drawings, X1-X2 directions represent widthdirections of the projector 1, Y1-Y2 directions represent heightdirections of the projector 1, and Z1-Z2 directions represent depthdirections of the projector 1. Moreover, in the following description,it is assumed that the radiation window 3 side of the projector 1corresponds to the top of the projector 1 and the side of the projector1 opposite to the radiation window 3 corresponds to the bottom of theprojector 1.

FIG. 2 is a block diagram illustrating a configuration of the projector1.

As illustrated in FIG. 2, the projector 1 includes a power source 4, amain switch (SW) 5, an operation unit 7, an external interface (I/F) 9,a system control unit 10, a fan 20, and an optical engine 15.

The power source 4 is coupled to a commercial power source, convertsvoltage and frequency of the commercial power for the internal circuitsof the projector 1, and supplies the power to each of the system controlunit 10, the fan 20, and the optical engine 15.

The main switch 5 is switched ON or OFF by a user to power on or off theprojector 1.

While the power source 4 is coupled to the commercial power source via apower cord, if the main switch 5 is switched ON, the power source 4starts supplying power to the respective components of the projector 1,and if the main switch 5 is switched OFF, the power source 4 stops tosupply the power to the respective components of the projector 1.

The operation unit 7 includes buttons configured to receive variousinput operations by a user. For example, the operation unit 7 isprovided on a top surface of the projector 1. The operation unit 7 isconfigured to receive input operations by the user, such as selection ofa size of a projection image, selection of a color tone, and adjustmentof a focus. The user's input operation received by the operation unit 7is sent to the system control unit 10.

The external interface 9 includes connection terminals coupled to, forexample, a personal computer (PC) or a digital camera, and is configuredto supply (output) image data, which is received from the coupledapparatus, to the system control unit 10.

The system control unit 10 includes an image control unit 11 and a drivecontrol unit 12. For example, the system control unit 10 may include aCPU (a processor), a ROM, and a RAM as hardware components thereof. Thefunctions of the system control unit 10 may be implemented byinstructions from the CPU when at least one program read from the ROMinto the RAM is executed by the CPU.

The image control unit 11 is configured to control a digital micromirrordevice (DMD) 551 provided in an image generating unit 50 of the opticalengine 15 based on the image data received from the external interface9, to generate an image to be projected on the screen S.

The drive control unit 12 is configured to move a movable unit 55 (whichis provided to be movable in the image generating unit 50) and control aposition of the DMD 551 provided in the movable unit 55.

The fan 20 is rotated under the control of the system control unit 10 tocool a light source 30 of the optical engine 15.

The optical engine 15 includes the light source 30, a lighting opticalsystem unit 40, the image generating unit 50, and a projection opticalsystem unit 60. The optical engine 15 is controlled by the systemcontrol unit 10 to project an image on a screen S as illustrated in FIG.1.

Examples of the light source 30 include a mercury high-pressure lamp, axenon lamp, and a light emitting diode (LED). The light source 30 iscontrolled by the system control unit 10 to emit illumination light tothe DMD 551 provided on the image generating unit 50 via the lightingoptical system unit 40.

The lighting optical system unit 40 includes, for example, a colorwheel, a light tunnel, and relay lenses. The lighting optical systemunit 40 is configured to guide the illumination light emitted from thelight source 30 to the DMD 551 provided in the image generating unit 50.

The image generating unit 50 includes a fixed unit 51, which is fixedand supported on the image generating unit 50, and the movable unit 55,which is supported to be movable relative to the fixed unit 51. Themovable unit 55 includes the DMD 551 and a position of the movable unit55 relative to the fixed unit 51 is controlled by the drive control unit12 of the system control unit 10. The DMD 551 is an example of an imagegenerating part. The DMD 551 is controlled by the image control unit 11of the system control unit 10. The DMD 551 is configured to modulate theillumination light received from the lighting optical system unit 40 andgenerate a projection image based on the received light.

The projection optical system unit 60 is an example of a projectingpart. The projection optical system unit 60 includes, for example, aplurality of projection lenses and a mirror. The projection opticalsystem unit 60 is configured to enlarge the image generated by the DMD551 of the image generating unit 50, and project the enlarged image onthe screen S.

Next, a configuration of the optical engine 15 of the projector 1 isexplained.

FIG. 3 is a perspective view of the optical engine 15 of the projector1. As illustrated in FIG. 3, the optical engine 15 includes the lightsource 30, the lighting optical system unit 40, the image generatingunit 50, and the projection optical system unit 60. The optical engine15 is provided inside of the projector 1.

The light source 30 is provided on a side surface of the lightingoptical system unit 40. The light source 30 is configured to emit lightin the X2 direction. The lighting optical system unit 40 is configuredto guide the light emitted from the light source 30 to the imagegenerating unit 50. The image generating unit 50 is provided beneath thelighting optical system unit 40. The image generating unit 50 isconfigured to generate a projection image based on the light receivedfrom the lighting optical system unit 40. The projection optical systemunit 60 is provided above the lighting optical system unit 40. Theprojection optical system unit 60 is configured to project theprojection image generated by the image generating unit 50 onto thescreen S, which is provided outside the projector 1.

The optical engine 15 of this embodiment is configured to project theimage based on the light emitted from the light source 30 in an upwarddirection. Alternatively, the optical engine 15 may be configured toproject the image in a horizontal direction.

FIG. 4 is a diagram illustrating the lighting optical system unit 40according to the embodiment.

As illustrated in FIG. 4, the lighting optical system unit 40 includes acolor wheel 401, a light tunnel 402, relay lenses 403 and 404, acylinder mirror 405, and a concave mirror 406.

The color wheel 401 is, for example, a disc-like component, in whichcolor filters of R (red), G (green), and B (blue) are provided atdifferent portions in a circumferential direction thereof. The colorwheel 401 is rotated at high speed so that the light emitted from thelight source 30 is divided into RGB color light beams in a time-divisionmanner.

The light tunnel 402 is, for example, a rectangular tube-like componentformed of bonded glass sheets. The light tunnel 402 functions to performmultipath reflection of the RGB color light beams passing through thecolor wheel 401 by the internal surfaces thereof for equalization ofluminance distribution, and guides the light beams to the relay lenses403 and 404.

The relay lenses 403 and 404 function to correct the chromaticaberrations on the optical axis of the light beams emitted from thelight tunnel 402 and convert the light beams into converging lightbeams.

The cylinder mirror 405 and the concave mirror 406 function to reflectthe light emitted from the relay lenses 403 and 404 to the DMD 551provided in the image generating unit 50. The DMD 551 is configured tomodulate the light reflected from the concave mirror 406 and generate aprojection image.

FIG. 5 is a diagram illustrating an internal configuration of theprojection optical system unit 60 according to the embodiment.

As illustrated in FIG. 5, the projection optical system unit 60 includesprojection lenses 601, a folding mirror 602, and a curved surface mirror603, which are provided in a housing of the projection optical systemunit 60.

The projection lenses 601 include a plurality of lenses. The projectionlenses 601 function to focus the projection image generated by the DMD551 of the image generating unit 50 onto the folding mirror 602. Thefolding mirror 602 and the curved surface mirror 603 function to reflectthe focused projection image so as to be enlarged, and project the imageon the screen S, which is provided outside the projector 1.

FIG. 6 is a perspective view of the image generating unit 50 accordingto the embodiment. FIG. 7 is a side view of the image generating unit 50according to the embodiment.

As illustrated in FIG. 6 and FIG. 7, the image generating unit 50includes the fixed unit 51 and the movable unit 55. The fixed unit 51 isfixedly supported by the lighting optical system unit 40. The movableunit 55 is movably supported by the fixed unit 51.

The fixed unit 51 includes a top plate 511 as a first fixed plate, and abase plate 512 as a second fixed plate. The top plate 511 and the baseplate 512 are held in parallel and face each other via a predeterminedgap between the top plate 511 and the base plate 512. The fixed unit 51is fixed to the bottom of the lighting optical system unit 40 with fourscrews 520 illustrated in FIG. 6.

The movable unit 55 includes the DMD 551, a movable plate 552 as a firstmovable plate, a DMD base plate 553 as a second movable plate, and aheat sink 554 as a heat radiating member. The movable unit 55 issupported by the fixed unit 51 so that the movable unit 55 is movable.

The DMD 551 is provided on the top surface of the DMD base plate 553.The DMD 551 has an image generation surface, in which a plurality ofmovable micromirrors are arrayed in a lattice formation. A specularsurface of each of the micromirrors of the DMD 551 is provided to betiltable (slantingly rotatable) around a torsion axis. The ON/OFF driveof each of the micromirrors of the DMD 551 is performed based on animage signal transmitted from the image control unit 11 of the systemcontrol unit 10. Here, the DMD 551, which is an example of an imagegenerating part and receives illumination light emitted from the lightsource 30 to generate an image, is provided on the DMD base plate 553,which is an example of a movable part. The projection optical systemunit 60 projects the image generated by the DMD 551.

For example, in an ON state, an inclination angle of the micromirror iscontrolled so that the micromirror reflects the illumination light fromthe light source 30 to the projection optical system unit 60. In an OFFstate, the inclination angle of the micromirror is controlled so thatthe micromirror reflects the illumination light from the light source 30to an OFF light plate (which is not illustrated).

In this manner, in the DMD 551, the inclination angle of each of themicromirrors of the DMD 551 is controlled based on the image signaltransmitted from the image control unit 11, and the illumination lightemitted from the light source 30 and guided by the lighting opticalsystem unit 40 is modulated and the projection image is generated. Inother words, the micromirrors of the DMD 551 may modulate theillumination light based on the image signal.

The movable plate 552 is supported between the top plate 511 and thebase plate 512 of the fixed unit 51. The movable plate 552 is providedto be movable in a direction parallel to the surface of the movableplate 552.

The DMD base plate 553 is provided between the top plate 511 and thebase plate 512. The DMD base plate 553 is coupled to the bottom surfaceside of the movable plate 552. The DMD 551 is provided on the topsurface of the DMD base plate 553. The DMD base plate 553 is displaced(moved) together with the movable plate 552 that is provided to bemovable.

The heat sink 554 radiates (dissipates) heat generated in the DMD 551.The heat sink 554 prevents the temperature of the DMD 551 from rising toreduce occurrence of problems such as malfunction and failure, due tothe temperature rise of the DMD 551. The heat sink 554 is provided to bemoved together with the movable plate 552 and the DMD base plate 553 sothat the heat sink 554 can always radiate the heat generated in the DMD551.

(Fixed Unit 51)

FIG. 8 is an exploded perspective view of the fixed unit 51 according tothe embodiment.

As illustrated in FIG. 8 and FIG. 9, the fixed unit 51 includes the topplate 511 and the base plate 512.

For example, the top plate 511 and the base plate 512 are flat-shapedplate members constituted with magnetic material such as iron orstainless steel. The top plate 511 and the base plate 512 are supportedby a plurality of columnar supports 515 so that the top plate 511 andthe base plate 512 are held in parallel via the predetermined gap.

The top plate 511 has a central hole 514 formed on a position facing theDMD 551 of the movable unit 55. Further, the base plate 512 has aheat-transfer hole 519 formed on a position facing the DMD 551. Aheat-transfer part of the heat sink 554 is inserted into theheat-transfer hole 519.

An upper end portion of each of the columnar supports 515 is insertedinto a corresponding one of support holes 516, which are formed on thetop plate 511. A lower end portion of each of the columnar supports 515is inserted into a corresponding one of support holes 517, which areformed on the base plate 512. The columnar supports 515 support the topplate 511 and the base plate 512 in parallel so as to form the constantdistance (gap) between the top plate 511 and the base plate 512.

The top plate 511 has screw holes 518 provided at four locations aroundthe central hole 514. According to the embodiment, the two screw holes518 are formed so as to be in communication with the central hole 514.The top plate 511 is fixed to the bottom part of the lighting opticalsystem unit 40 with the screws 520 (illustrated in FIG. 6) that areinserted into the respective screw holes 518.

The top plate 511 has a plurality of support holes 526 for rotatablyholding support balls 521 that support, from the upper side, the movableplate 552 so that the movable plate 552 is movable. Further, the baseplate 512 has a plurality of support holes 522 for rotatably holdingsupport balls 521 that support, from the lower side, the movable plate552 so that the movable plate 552 is movable.

Upper ends of the respective support holes 526 of the top plate 511 areclosed by lid members 527, and the support holes 526 of the top plate511 hold the support balls 521 rotatably. Cylindrical holding members523, each of which has an internal thread groove formed on an innerperipheral surface of the holding member 523, are inserted in thesupport holes 522 of the base plate 512. Lower end sides of the holdingmembers 523 are closed (covered) by the positioning screws 524. Theholding members 523 hold the support balls 521 so that the support balls521 are rotatable.

The support balls 521, which are rotatably held at the top plate 511 andthe base plate 512, are respectively in contact with the movable plate552. Hence, the support balls 521 movably support the movable plate 552from the both surfaces of the movable plate 552.

FIG. 9 is a diagram illustrating a structure of supporting the movableplate 552 by the fixed unit 51 according to the embodiment.

As illustrated in FIG. 9, at the top plate 511, the support balls 521are rotatably held at the support holes 526 of which the upper end sidesare closed by the lid members 527. At the base plate 512, the supportballs 521 are rotatably held by the holding members 523, which areinserted in the support holes 522.

Each of the support balls 521 is held so that at least part of thesupport ball 521 protrudes from the support hole 522 or the support hole526. Each of the support balls 521 is in contact with the movable plate552 provided between the top plate 511 and the base plate 512. The topsurface and the bottom surface of the movable plate 552 are supported bythe plurality of rotatable support balls 521 so that the movable plate552 is movable in a direction parallel to the top and bottom surfaces ofthe movable plate 552.

Moreover, the amount of protrusion of the support ball 521, which isprovided on the base plate 512 side, from the upper end of the holdingmember 523 is changed depending on a position of the positioning screw524. For example, if the positioning screw 524 is displaced in the Z1direction (upward), the amount of protrusion of the support ball 521 isincreased and the distance (gap) between the base plate 512 and themovable plate 552 is increased. On the other hand, if the positioningscrew 524 is displaced in the Z2 direction (downward), the amount ofprotrusion of the support ball 521 is decreased and the gap between thebase plate 512 and the movable plate 552 is decreased.

In this way, the gap between the base plate 512 and the movable plate552 may be appropriately adjusted by changing the amount of protrusionof the support ball 521 by use of the positioning screw 524.

As illustrated in FIG. 8, a plurality of position detecting magnets 541are provided on the top surface of the base plate 512. Each of theposition detecting magnets 541 is constituted with two permanent magnetseach having a rectangular parallelepiped shape. The two permanentmagnets are arranged in parallel to each other in the longitudinaldirection. Each of the position detecting magnets 541 forms a magneticfield, which reaches (affects) the DMD base plate 553 provided betweenthe top plate 511 and the base plate 512.

Hall elements, each of which is provided on the bottom surface of theDMD base plate 553, and the position detecting magnets 541 constitute aposition detecting unit that detects a position of the DMD 551.

Further, a plurality of driving magnets 531 a, 531 b, and 531 c areprovided on the bottom surface of the base plate 512. Note that thedriving magnet 531 c is not illustrated in FIG. 8. In the followingdescriptions, the driving magnets 531 a, 531 b, and 531 c may bereferred to as the “driving magnet(s) 531” as appropriate.

Each of the driving magnets 531 is constituted with two magnets eachhaving a rectangular parallelepiped shape. The two magnets are arrangedin parallel in the longitudinal. Each of the driving magnets 531 forms amagnetic field, which reaches (affects) the heat sink 554. Drivingcoils, provided on the top surface of the heat sink 554, and the drivingmagnets 531 constitute a driving unit that moves the movable unit 55.

Note that the number, positions, and the like of the support balls 521and the columnar supports 515, which are provided on the fixed unit 51,are not limited to the configuration described in the embodiment.

(Movable Unit 55)

FIG. 10 is an exploded perspective view of the movable unit 55 accordingto the embodiment. FIG. 11 is a side view of the movable unit 55according to the embodiment.

As illustrated in FIG. 10 and FIG. 11, the movable unit 55 includes theDMD 551, the movable plate 552, the DMD base plate 553, and the heatsink 554.

As described above, the movable plate 552 is provided between the topplate 511 and the base plate 512 of the fixed unit 51, and supported bythe plurality of support balls 521 to be movable in the directionparallel to the top and bottom surfaces of the movable plate 552.

As illustrated in FIG. 10, the movable plate 552 has a central hole 570at a position facing the DMD 551, which is mounted on the DMD base plate553. Further, the movable plate 552 has through holes 572, into whichthe screws 520, which fix the top plate 511 to the lighting opticalsystem unit 40, are inserted. Further, the movable plate 552 hascoupling holes 573, which are used for coupling to the DMD base plate553, and movable range restriction holes 571 at positions correspondingto the columnar supports 515 of the fixed unit 51.

For example, in a state in which the gap is adjusted to make the surfaceof the movable plate 552 and the image generation surface of the DMD 551be parallel by the screws that are inserted into the respective couplingholes 573, the movable plate 552 and the DMD base plate 553 are coupledand fixed by an adhesive agent.

Here, the movable plate 552 moves in parallel to the surface, and theDMD 551 moves together with the movable plate 552 as well. Accordingly,if the surface of the movable plate 552 and the image generation surfaceof the DMD 551 are not parallel, there is a possibility that the imagegeneration surface of the DMD 551 inclines with respect to the movingdirection and the image is disturbed (disordered).

Thus, according to the embodiment, the screws are inserted into thecoupling holes 573 to adjust the gap between the movable plate 552 andthe DMD base plate 553, and the surface of the movable plate 552 and theimage generation surface of the DMD 551 are held in parallel. Thereby,it is possible to prevent the image quality from decreasing.

The columnar supports 515 of the fixed unit 51 are inserted in themovable range restriction holes 571. For example, if the movable plate552 is greatly displaced (moved) due to vibration or certainmalfunction, the columnar supports 515 come in contact with the movablerange restriction holes 571 to restrict the movable range of the movableplate 552.

Note that the number, the positions, and the shapes, and the like of themovable range restriction holes 571 and the coupling holes 573 are notlimited to the configuration described in the embodiment. Aconfiguration, which is different from that of the embodiment, may beused to couple the movable plate 552 and the DMD base plate 553.

The DMD base plate 553 is provided between the top plate 511 and thebase plate 512 of the fixed unit 51, and coupled to the bottom surfaceof the movable plate 552 as described above.

The DMD 551 is provided on the top surface of the DMD base plate 553.The DMD 551 is coupled to the DMD base plate 553 via a socket 557. Acover 5580 covers around the DMD 551. The DMD 551 is exposed to the topsurface side of the movable plate 552 through the central hole 570 ofthe movable plate 552. In other words, the DMD 551 may protrude thoroughthe central hole 570.

The DMD base plate 553 has through holes 555 into which the screws 520,which fix the top plate 511 to the lighting optical system unit 40, areinserted. Further, the DMD base plate 553 has cutouts 558 at portionsfacing coupling columns 561 of the heat sink 554 so that the movableplate 552 is fixed to the coupling columns 561 of the heat sink 554.

For example, if the movable plate 552 and the DMD base plate 553 arejointly fastened to the coupling columns 561 of the heat sink 554, thereis a possibility that the DMD base plate 553 is distorted, the imagegeneration surface of the DMD 551 inclines with respect to the movingdirection, and the image is disturbed. Thus, the cutouts 558 are formedon outer edge portions of the DMD base plate 553 so that the couplingcolumns 561 of the heat sink 554 are coupled to the movable plate 552avoiding the DMD base plate 553.

Because the heat sink 554 is coupled to the movable plate 552 accordingto the above described configuration, the possibility that the DMD baseplate 553 is distorted due to receiving a load from the heat sink 554 isreduced. Accordingly, it is possible to hold the image generationsurface of the DMD 551 in parallel to the moving direction and tomaintain the image quality.

Further, the cutouts 558 of the DMD base plate 553 are formed to includeportions facing the support holes 522 of the base plate 512 so that thesupport balls 521, held by the base plate 512, contact the movable plate552 while avoiding the DMD base plate 553. According to such aconfiguration, at the DMD base plate 553, it is possible to preventoccurrence of distortion due to the load from the support balls 521 andto hold the image generation surface of the DMD 551 in parallel to themoving direction to maintain the image quality.

Note that the shapes of the cutouts 558 are not limited to the shapesdescribed in the embodiment. Through holes may be formed on the DMD baseplate 553 instead of the cutouts 558 if it is possible to make the DMDbase plate 553 be in non-contact with the coupling columns 561 of theheat sink 554 and the support balls 521. In other words, the DMD baseplate 553 may have at least one cutout or at least one hole, and atleast one coupling member, which couples the heat radiating part 556 tothe movable plate 552 through the at least one cutout or the at leastone hole in a state in which the DMD base plate 553 is not in contactwith the at least one coupling member.

As illustrated in FIG. 11, on the bottom surface of the DMD base plate553, the hall elements 542 as magnetic sensors are provided at positionsfacing the position detecting magnets 541 provided on the top surface ofthe base plate 512. The hall elements 542, provided at the DMD baseplate 553, and the position detecting magnets 541, provided at the baseplate 512, constitute a position detecting unit that detects a positionof the DMD 551.

As illustrated in FIG. 10 and FIG. 11, the heat sink 554 includes a heatradiating part 556, the coupling columns 561, and a heat-transfer part563. The heat-transfer part 563 is not illustrated in FIG. 10.

The heat radiating part 556 is coupled to the DMD base plate 553. Thebase plate 512 is provided (sandwiched) between the heat radiating part556 and the DMD base plate 553. A plurality of fins are formed on thelower portion of the heat radiating part 556. The heat radiating part556 radiates (dissipates) heat generated in the DMD 551. As illustratedin FIG. 10, concave portions 582 are formed on the top surface of theheat radiating part 556. Driving coils 581 a, 581 b, and 581 c, whichare provided on a flexible base plate 580, are attached to the concaveportions 582. In the following description, the driving coils 581 a, 581b, and 581 c may be referred to as the “driving coil(s) 581” asappropriate.

The concave portions 582 are formed on positions facing the drivingmagnets 531 that are provided on the bottom surface of the base plate512. The driving coils 581, which are attached to the concave portions582, and the driving magnets 531, which are provided on the bottomsurface of the base plate 512, constitute a driving unit that moves themovable unit 55 relative to the fixed unit 51.

Further, the heat radiating part 556 has through holes 562, into whichthe screws 520, which fix the top plate 511 to the lighting opticalsystem unit 40, are inserted.

The coupling columns 561 are formed on three locations to extend fromthe top surface of the heat radiating part 556 in the Z1 direction. Themovable plate 552 is fixed to respective upper ends of the couplingcolumns 561 with screws 564 (illustrated in FIG. 11). The couplingcolumns 561 are coupled to the movable plate 552 without contacting theDMD base plate 553 because of the cutouts 558 formed on the DMD baseplate 553.

As illustrated in FIG. 11, the heat-transfer part 563 extends from thetop surface of the heat radiating part 556 in the Z1 direction and is incontact with the bottom surface of the DMD 551 to transfer, to the heatradiating part 556, heat generated in the DMD 551. For example, aheat-transfer sheet may be provided between the DMD 551 and the upperend surface of the heat-transfer part 563 in order to enhance heatconductivity. In such a case, the thermal conductivity between theheat-transfer part 563 of the heat sink 554 and the DMD 551 is enhancedby the heat-transfer sheet, and thereby the effect of cooling the DMD551 is enhanced.

The through holes 572 of the movable plate 552, the through holes 555 ofthe DMD base plate 553, and the through holes 562 of the heat sink 554are formed to face each other in the Z1-Z2 direction. The screws 520,which fix the top plate 511 to the lighting optical system unit 40, areinserted into the through holes 562, the through holes 555, and thethrough holes 572, from the lower side. In other words, the throughholes 562, the through holes 555, and the through holes 572 may berespectively overlapped in the Z1-Z2 direction. In other words, at leastone position detecting magnet 541 and at least one hall element 541 maybe arranged between the DMD base plate 553 and the base plate 512 or thetop plate 511 to face each other.

Here, a space corresponding to the thickness of the DMD 551 and thesocket 557 is generated between from the surface of the DMD base plate553 to the image generation surface of the DMD 551. If the DMD baseplate 553 is arranged above the top plate 511, the space from thesurface of the DMD base plate 553 to the image generation surface of theDMD 551 becomes a dead space and there is a possibility that theapparatus configuration grows in size.

According to the embodiment, the DMD base plate 553 is provided betweenthe top plate 511 and the base plate 512 to arrange the top plate 511 inthe space from the surface of the DMD base plate 553 to the imagegeneration surface of the DMD 551. According to such a configuration, itis possible to effectively utilize the space from the surface of the DMDbase plate 553 to the image generation surface of the DMD 551 to reducethe height in the Z1-Z2 direction and to downsize the apparatusconfiguration. Thus, the image generating unit 50 according to theembodiment can be installed not only in a large projector but also in asmall projector. That is, the versatility of the image generating unit50 according to the embodiment can be enhanced.

(Driving Unit)

FIG. 12 is an exploded perspective view of the driving unit according tothe embodiment.

The driving unit according to the embodiment includes the drivingmagnets 531, provided on the base plate 512, and the driving coils 581,provided on the heat sink 554.

Each of the driving magnets 531 a and 531 b is constituted with twopermanent magnets of which the longitudinal directions are parallel withthe X1-X2 direction. The driving magnet 531 c is constituted with twopermanent magnets of which the longitudinal directions are parallel withthe Y1-Y2 direction. Each of the driving magnets 531 forms a magneticfield, which reaches (affects) the heat sink 554.

Each of the driving coils 581 is formed of electric wire wound around anaxis parallel to the Z1-Z2 direction, and is attached to the concaveportion 582 formed on the top surface of the heat radiating part 556 ofthe heat sink 554.

In the state in which the movable unit 55 is supported by the fixed unit51, the driving magnets 531 of the base plate 512 and the driving coils581 of the heat sink 554 are provided to face each other, respectively.When electric current is caused to flow through the driving coils 581,Lorentz force to be driving force to move the movable unit 55 isgenerated by the magnetic fields formed by the driving magnets 531.

Receiving the Lorentz force as the driving force generated between thedriving magnets 531 and the driving coils 581, the movable unit 55 isdisplaced to linearly move or rotate in the X-Y plane relative to thefixed unit 51.

According to the embodiment, as a first driving unit, the driving coil581 a and the driving magnet 531 a, and the driving coil 581 b and thedriving magnet 531 b are provided to face each other in the X1-X2direction. When electric current flows through the driving coils 581 aand 581 b, the Lorentz force in the Y1 direction or the Y2 direction isgenerated.

The movable unit 55 is moved in the Y1 direction or the Y2 direction bythe Lorentz force generated at the driving coils 581 a and 581 b. Themovable unit 55 is rotated in the XY plane, by the Lorentz forcegenerated in opposite directions at the driving coils 581 a and 581 b.

For example, when electric current is supplied so that the Lorentz forcein the Y1 direction is generated at the driving coil 581 a and theLorentz force in the Y2 direction is generated at the driving coil 581b, the movable unit 55 rotates counterclockwise in a top view. On theother hand, when electric current is supplied so that the Lorentz forcein the Y2 direction is generated at the driving coil 581 a and theLorentz force in the Y1 direction is generated at the driving coil 581b, the movable unit 55 rotates clockwise in a top view.

Further, according to the embodiment, the driving coil 581 c and thedriving magnet 531 c are provided as a second driving unit. The drivingmagnet 531 c is arranged so that the longitudinal direction of thedriving magnet 531 c is orthogonal to the longitudinal direction of thedriving magnets 531 a and 531 b. In such a configuration, when electriccurrent flows through the driving coil 581 c, Lorentz force in the X1direction or the X2 direction is generated. The movable unit 55 is movedin the X1 direction or the X2 direction by the Lorentz force generatedat the driving coil 581 c.

The magnitude and direction of the electric current flowing through eachof the driving coils 581 are controlled by the drive control unit 12 ofthe system control unit 10. The drive control unit 12 controls (changes)the magnitude and direction of the electric current to be supplied toeach of the driving coils 581 to control the direction of movement (orrotation), the amount of movement and the rotational angle of themovable plate 552.

The base plate 512 has a heat-transfer hole 559 provided on a positionfacing the DMD 551 provided on the DMD base plate 553. The heat-transferpart 563 of the heat sink 554 is inserted into the heat-transfer hole559. Further, the base plate 512 has through holes 560, into which thescrews 520, which fix the top plate 511 to the lighting optical systemunit 40, are inserted.

(Position Detecting Unit)

FIG. 13 is an exploded perspective view of an example of a configurationincluding the position detecting unit according to the embodiment. FIG.14 is an exploded side view of the example of the configurationincluding the position detecting unit according to the embodiment.

The position detecting unit according to the embodiment includes theposition detecting magnets 541, provided on the base plate 512, and thehall elements 542, provided on the DMD base plate 553. The positiondetecting magnets 541 and the hall elements 542 are arranged to faceeach other in the Z1-Z2 direction.

Each of the hall elements 542 is an example of a magnetic sensor. Thehall element 542 transmits, to the drive control unit 12 of the systemcontrol unit 10, a signal in accordance with a change of a magnetic fluxdensity from the position detecting magnet 541 that is provided to facethe hall element 541. The drive control unit 12 detects, based on thesignals transmitted from the Hall elements 542, the position of the DMD551 provided on the DMD base plate 553.

Here, according to the embodiment, the base plate 512 and the top plate511 formed with magnetic material serve as yoke boards and constitute amagnetic circuit, which includes the position detecting magnets 541.Further, the magnetic flux generated at the driving unit, which isprovided between the base plate 512 and the heat sink 554 and includesthe driving magnets 531 and the driving coils 581, is concentrated inthe base plate 512, which functions as the yoke board, and thus, theleakage to the position detecting unit is reduced.

Accordingly, influence of the magnetic fields generated by the drivingunit including the driving magnets 531 and the driving coils 581 isreduced at the hall elements 542 provided on the bottom surface side ofthe DMD base plate 553. Therefore, the hall elements 542 can outputsignals in accordance with the change of the magnetic flux density ofthe position detection magnets 541 without being influenced by themagnetic fields generated at the driving unit. Thus, it is possible forthe driving control unit 12 to detect (determine) the position of theDMD 551 with high accuracy.

In this way, the drive control unit 12 can detect the position of theDMD 551 with high accuracy based on the output of the hall elements 542in which influence from the driving unit is reduced. Accordingly, thedrive control unit 12 can control the magnitude and the direction of theelectric current flowing through the driving coils 581 in accordancewith the detected position of the DMD 551 and can control the positionof the DMD 551 with high accuracy.

It should be noted that the configuration of the driving unit and theconfiguration of the position detecting unit are not limited to theconfigurations described in the embodiment. The number, positions, etc.,of the driving magnets 531 and the driving coils 581 as the driving unitmay be different from those described in the embodiment as long as themovable unit 55 can be moved to an arbitrary position. For example, thedriving unit, which moves the movable unit 55 relative to the fixed unit51, may include at least one driving magnet and at least one drivingcoil, which faces the at least one driving magnet. The at least onedriving magnet and the at least one driving coil may be arranged betweenthe base plate 512 and the heat radiating part 556. Further, the number,positions, etc., of the position detecting magnets 541 and the hallelements 542 as the position detecting unit may be different from thosedescribed in the embodiment as long as it is possible to detect theposition of the DMD 551.

For example, the position detecting magnets 541 may be disposed on thetop plate 511 and the hall elements 542 may be disposed on the movableplate 552. Further, for example, the position detecting unit may bedisposed between the base plate 512 and the heat sink 554, and thedriving unit may be disposed between the top plate 511 and the baseplate 512. However, it is preferable to provide a yoke board between thedriving unit and the position detecting unit in order to reduceinfluence of the magnetic fields from the driving unit to the positiondetecting unit. Further, it is preferable to provide the driving magnets531 and the position detecting magnets 541 on the top plate 511 or thebase plate 512 of the fixed unit 51, because, otherwise, there is apossibility that the weight of the movable unit 55 increases and itbecomes difficult to control the position of the movable unit 55.

Further, the top plate 511 and the base plate 512 may be partially madeof magnetic material as long as it is possible to reduce the leakage ofthe magnetic flux from the driving unit to the position detecting unit.For example, the top plate 511 and the base plate 512 may be formed bystacking multiple members including a flat-plate-shaped member or asheet-shaped member made of magnetic material. The top plate 511 may bemade of non-magnetic material as long as the base plate 512 is at leastpartially made of magnetic material and functions as a yoke board forpreventing the leakage of the magnetic flux from the driving unit to theposition detecting unit.

<Image Projection>

As described above, according to the projector 1 of the embodiment, theDMD 551, which generates a projection image, is mounted on the movableunit 55, and the position of the DMD 551 is controlled by the drivecontrol unit 12 of the system control unit 10.

For example, the drive control unit 12 controls the position of themovable unit 55 in such a way that the movable unit 55 moves at highspeed between a plurality of positions away from each other by less thanan array interval of the micromirrors of the DMD 551 at a predeterminedcycle corresponding to a frame rate when projecting an image. At thistime, the image control unit 11 transmits an image signal to the DMD 551to generate a projection image shifted according to each of thepositions.

For example, the drive control unit 12 reciprocates the DMD 551 at apredetermined cycle between a position P1 and a position P2 away fromeach other in the X1-X2 direction and the Y1-Y2 direction by less thanthe array interval of the micromirrors of the DMD 551. At this time, theimage control unit 11 controls the DMD 551 to generate the projectionimage shifted according to each of the positions so that it becomespossible to make the resolution of the projection image to be aboutdouble of the resolution of the DMD 551. Moreover, the number of movingpositions of the DMD 551 may be increased to make the resolution of theprojection image to be more than double of the resolution of the DMD551. In other words, the drive control unit 12 may control the drivingunit, which moves the movable unit 55 relative to the fixed unit 51, tomove the movable unit 55 by a distance less than the array interval ofthe micromirrors. In other words, the drive control unit 12 may controlthe electric current, which flows through the driving coils 581, to movethe movable unit 51.

In this way, the drive control unit 12 shifts (moves) the DMD 551together with the movable unit 55, and the image control unit 11controls the DMD 551 to generate the projection image according to theposition of the DMD 551. Hence, it is possible to project the imagewhose resolution is made higher than or equal to the resolution of theDMD 551.

According to the projector 1 of the embodiment, the drive control unit12 controls the DMD 551 so that the DMD 551 is rotated integrally withthe movable unit 55. Thereby, it is possible to rotate the projectionimage without reducing the size of the projection image. For example, ina projector, in which an image generating part such as a DMD is fixed,it is impossible to rotate a projection image without shrinking theprojection image while keeping the aspect ratio of the projection image.In contrast, according to the projector 1 of the embodiment, it ispossible to rotate the DMD 551, and thus, it is possible to rotate theprojection image to adjust the tilt without shrinking the projectionimage.

As described above, according to the image generating unit 50 of theembodiment, the DMD 551 is provided to be movable, and it is possible toshift (move) the DMD 551 to generate the image having high resolution.

Further, according to the embodiment, the DMD base plate 553 is disposedbetween the top plate 511 and the base plate 512, and the top plate 511is provided in the space from the surface of the DMD base plate 553 tothe image generation surface of the DMD 551. Thus, it is possible toeffectively utilize the space from the surface of the DMD base plate 553to the image generation surface of the DMD 551, to downsize the imagegenerating unit 50, and to enhance the versatility.

Furthermore, according to the embodiment, the base plate 512 and the topplate 511, constituted with magnetic materials, serve as yoke boards andconstitute a magnetic circuit with the position detecting magnets 541 ofthe position detecting unit, and influence of the magnetic fields,generated at the driving unit, on the position detecting unit isreduced. Thus, the drive control unit 12 can detect, with high accuracy,the position of the DMD 551 that shifts at high speed based on theoutput of the hall elements 542, and can control the position of the DMD551 with high accuracy.

The image generating unit and the image projecting apparatus accordingto the present disclosure are not limited to the above describedembodiment, but various variations and modifications may be made withoutdeparting from the scope of the present disclosure.

What is claimed is:
 1. An image generating unit comprising: a fixed unitincluding a first fixed plate and a second fixed plate; and a movableunit movably supported by the fixed unit, wherein the movable unitincludes a movable part movably supported between the first fixed plateand the second fixed plate; an image generating part provided on themovable part and configured to receive illumination light to generate animage; and a heat radiating part coupled to the movable part andconfigured to radiate heat generated in the image generating part, thesecond fixed plate being sandwiched between the heat radiating part andthe movable part, wherein the second fixed plate has a hole into which aheat-transfer part of the heat radiating part is inserted, wherein theimage generating unit includes a driving unit, including at least onedriving magnet and at least one driving coil arranged between the secondfixed plate and the heat radiating part, and configured to move themovable unit relative to the fixed unit, the at least one driving magnetfacing the at least one driving coil, wherein the image generating unitincludes a drive control unit configured to control the driving unit,wherein the image generating part has a digital micromirror device inwhich a plurality of micromirrors that modulate the illumination lightbased on an image signal are arrayed, and wherein the drive control unitcontrols the driving unit to move, at a predetermined cycle, the movableunit by a distance less than an array interval of the plurality ofmicromirrors.
 2. The image generating unit according to claim 1, whereinthe movable unit includes a movable plate movably provided between thefirst fixed plate and the movable part, wherein the movable part has atleast one cutout or at least one hole, and wherein the movable unitincludes at least one coupling member that couples the heat radiatingpart to the movable plate through the at least one cutout or the atleast one hole.
 3. The image generating unit according to claim 2,wherein the heat radiating part is coupled to the movable plate in astate in which the movable part is not in contact with the at least onecoupling member.
 4. An image projecting apparatus comprising: the imagegenerating unit according to claim 1; a light source configured to emitthe illumination light to the image generating part; and a projectingpart configured to project the image generated by the image generatingpart.